<!DOCTYPE html>
<html>
<head>
  <title>Using Dimensioning Links</title>
  <!-- Copyright 1998-2016 by Northwoods Software Corporation. -->
  <meta charset="UTF-8">
  <script src="go.js"></script>
  <link href="../assets/css/goSamples.css" rel="stylesheet" type="text/css" />  <!-- you don't need to use this -->
  <script src="goSamples.js"></script>  <!-- this is only for the GoJS Samples framework -->
  <script src="../extensions/DimensioningLink.js"></script>
  <script id="code">
    function init() {
      if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this
      var $ = go.GraphObject.make;

      myDiagram =
        $(go.Diagram, "myDiagramDiv",
          {
            initialContentAlignment: go.Spot.Center,
            "undoManager.isEnabled": true
          });

      // A simple resizable node
      myDiagram.nodeTemplate =
        $(go.Node, "Auto",
          { locationSpot: go.Spot.Center },
          new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
          { resizable: true },
          $(go.Shape, { strokeWidth: 0, fill: "lightgray" },
            new go.Binding("fill", "color")),
          $(go.TextBlock, { margin: 10 },
            new go.Binding("text", "key"))
        );

      // A generalized example template using a DimensioningLink.
      // Most usage might not have so many Bindings.
      myDiagram.linkTemplateMap.add("Dimensioning", 
        $(DimensioningLink,
          new go.Binding("fromSpot", "fromSpot", go.Spot.parse),
          new go.Binding("toSpot", "toSpot", go.Spot.parse),
          new go.Binding("direction"),
          new go.Binding("extension"),
          new go.Binding("inset"),
          $(go.Shape, { stroke: "gray" },
            new go.Binding("stroke", "color")),
          $(go.Shape, { fromArrow: "BackwardOpenTriangle", segmentIndex: 2, stroke: "gray" },
            new go.Binding("stroke", "color")),
          $(go.Shape, { toArrow: "OpenTriangle", segmentIndex: -3, stroke: "gray" },
            new go.Binding("stroke", "color")),
          $(go.TextBlock,
            {
              segmentIndex: 2,
              segmentFraction: 0.5,
              segmentOrientation: go.Link.OrientUpright,
              alignmentFocus: go.Spot.Bottom,
              stroke: "gray",
              font: "8pt sans-serif"
            },
            new go.Binding("text", "", showDistance).ofObject(),
            new go.Binding("stroke", "color"))
        ));

      // Return a string representing the distance between the two points.
      // This is the cartesian distance if this.direction is NaN;
      // otherwise it is the orthogonal distance along that axis.
      function showDistance(link) {
        var numpts = link.pointsCount;
        if (numpts < 2) return "";
        var p0 = link.getPoint(0);
        var pn = link.getPoint(numpts - 1);
        var ang = link.direction;
        if (isNaN(ang)) return Math.floor(Math.sqrt(p0.distanceSquaredPoint(pn))) + "";
        var rad = ang * Math.PI / 180;
        return Math.floor(Math.abs(Math.cos(rad) * (p0.x - pn.x)) +
                          Math.abs(Math.sin(rad) * (p0.y - pn.y))) + "";
      }

      myDiagram.model = new go.GraphLinksModel([
        { key: "Alpha", loc: "0 50" },
        { key: "Beta", loc: "150 0" },
        { key: "Gamma", loc: "100 150"}
      ], [
        { from: "Alpha", to: "Beta", category: "Dimensioning",
          fromSpot: "TopRight", toSpot: "TopLeft" },
        { from: "Alpha", to: "Beta", category: "Dimensioning",
          fromSpot: "TopLeft", toSpot: "TopRight", extension: 50, color: "blue" },
        { from: "Alpha", to: "Beta", category: "Dimensioning",
          fromSpot: "TopLeft", toSpot: "TopLeft", direction: 270, color: "green" },
        { from: "Alpha", to: "Beta", category: "Dimensioning",
          fromSpot: "BottomRight", toSpot: "BottomRight", direction: 90, color: "purple" },
        { from: "Alpha", to: "Beta", category: "Dimensioning",
          fromSpot: "Center", toSpot: "Center", extension: 50, direction: NaN, color: "red" },

        { from: "Gamma", to: "Gamma", category: "Dimensioning",
          fromSpot: "TopLeft", toSpot: "TopRight", direction: 0 },
        { from: "Gamma", to: "Gamma", category: "Dimensioning",
          fromSpot: "TopRight", toSpot: "BottomRight", direction: 90 },
        { from: "Gamma", to: "Gamma", category: "Dimensioning",
          fromSpot: "BottomRight", toSpot: "BottomLeft", direction: 180 },
        { from: "Gamma", to: "Gamma", category: "Dimensioning",
          fromSpot: "BottomLeft", toSpot: "TopLeft", direction: 270 }
    ]);
    }
  </script>
</head>
<body onload="init()">
  <div id="sample">
    <div id="myDiagramDiv" style="border: solid 1px black; width:100%; height:400px"></div>
    <p>
      This sample makes use of the DimensioningLink class, which inherits from the <a>Link</a> class.
      That class is defined at <a href="../extensions/DimensioningLink.js">DimensioningLink.js</a>.
    </p>
  </div>
</body>
</html>s